Dual tip fountain pen

ABSTRACT

A tubular barrel for holding an ink supply is fitted at its lower end with a pen-holding structure that incorporates two distinct writing tips, or styli. The pen structure is an assembly of a plug-like body, an elongate primary stylus member, spring means normally biasing the stylus member to an extended position, and a tubular shell secured to the body and having a secondary stylus portion encircling the extendable portion of the primary stylus member. The stylus member and the shell have cooperating shoulder portions to limit the spring biased extension of the primary stylus through the secondary stylus. Ink conducting means are formed longitudinally of the primary stylus, intercommunicating a spaced pair of chambers in the structure, the body and primary stylus having cooperating portions keying them together against relative angular displacement and, also, providing a fluid restriction aiding in the regulation of the ink flow through the ducting means under varying conditions of ink flow corresponding to use of the primary or secondary stylus.

United States Patent Basham [54] DUAL TIP FOUNTAIN PEN [72] Inventor: Lloyd P. Basham, 2745 Carmar Dr.,

Los Angeles, Calif. 90046 [22] Filed: Dec. 9, 1970 [21] Appl. No.: 96,484

[52] US. Cl ..401/230, 401/260 [51] Int. Cl ..B43k 5/18, 843k H06 [58] Field of Search ..40l/230, 256-260, 401/263, 264, 270, 261

[56] References Cited UNITED STATES PATENTS 3,247,828 4/1966 Basham ..401/230 2,753,845 7/1956 Mitssner ..40l/261 FOREIGN PATENTS OR APPLICATIONS 288,459 1 [1953 Switzerland ..401/260 Primary Examiner-Lawrence Charles Attorney-Fulwider, Patton, Rieber, Lee & Utecht 51 Aug. 29, 1972 [57] ABSTRACT A tubular barrel for holding an ink supply is fitted at its lower end with a pen-holding structure that incorporates two distinct writing tips, or styli. The pen structure is an assembly of a plug-like body, an elongate primary stylus member, spring means normally biasing the stylus member to an extended position, and a tubular shell secured to the body and havinga secondary stylus portion encircling the extendable portion of the primary stylus member. The stylus member and the shell have cooperating shoulder portions to limit the spring biased extension of the primary stylus through the secondary stylus. Ink conducting means are formed longitudinally of the primary stylus, intercommunicating a spaced pair of chambers in the structure, the body and primary stylus having cooperating portions keying them together against relative angular displacement and, also, providing a fluid restriction aiding in the regulation of the ink flow through the ducting means under varying conditions of ink flow corresponding to use of the primary or secondary stylus.

PATENTEDmszs 1912 INVENTOR. [1.09 0 4 545H4M DUAL TIP FOUNTAIN PEN BACKGROUND OF THE INVENTION The present invention relates to fountain pens of the type having dual styli, one of which is extendable and retractible within the other for inking dot areas or lines of different widths, e.g., hairlines, thin lines, medium and heavy width lines, and large oval or round dots. Pens of this species are disclosed in my prior US. Pat. No. 3,247,828.

Pens of this class are employed by writers of musical manuscripts, lyric writers, cartoonists, loftsmen and draftsmen. Within a single instrument the pen provides a means of making lines of a variety of uniform or variable widths, with a uniform dispersion of ink within the lines, and single dots of relatively large area. Accordingly, the pen must be capable of accommodating different rates of ink flow or metered increments of ink, without creating any blobs or uncontrolled surges of ink flow, especially during extension and retraction of the primary stylus member inwardly and outwardly of the secondary stylus. The pen of my present invention has improved inkflow characteristics during all of the different modes of its use and, also provides a radically simplified and inexpensive structure.

SUMMARY OF THE INVENTION A plug-like body is externally threaded for engagement with an interiorly tapped lower end of a fountain pen barrel, the latter comprising or containing a reservoir for the ink supply. An elongate, cylindrical spring pocket is integrally formed, preferably as a blind cavity, on the upper end of the plug-like body to project coaxially inwardly of the pen barrel, the spring pocket comprising a coaxial extension of a blind bore opening forwardly through the plug-like body. An annulus is defined between the spring pocket and the inner wall of the pen barrel in communication with a plurality of passages by means of which ink is conducted from the reservoir to the bore through the plug-like body, the passages bypassing the spring pocket.

A primary stylus member is telescopically slidably received within the bore of the plug-like body to be normally biased outwardly by a spring means contained in the spring pocket. An ink duct means extends longitudinally of the primary stylus member for conducting ink to a lower nib portion of the primary stylus. A secondary tubular stylus member has a shell-like portion fitted to a boss formed integrally on the lower end of the plug-like body, the arrangement being such that the primary stylus member is extendable and retractible through the secondary stylus. Cooperating shoulder means are defined on the primary stylus and secondary stylus for limiting extension of the primary stylus.

The nib portion of the primary stylus member is divided by a slit into an opposed pair of nibs, the roots of the pair terminating in a diametral bore through the stem of the primary stylus member and at radially outer ends having fluid communication with the duct means along the stem of the primary stylus member. In order to hold the pair of nibs of the primary stylus member in a desired angular orientation relative to the secondary stylus and to hold the duct means of the primary stylus member in registration with the ink passages of the plug-like body, means are provided, intermediate the plug-like body and the primary stylus, for keying these parts together in the desired angular orientation. The spring pocket defines a chamber in fluid communication with the upper end of the duct means of the prima ry stylus member. An annular vented chamber is defined at or adjacent the lower end of the stem portion of the primary stylus member between the boss and the internal cup portion of the secondary stylus. The keying means is adapted to provide a fluid restriction in the duct means of the primary stylus member, between these two chambers, in order to properly regulate flow of ink through the duct means of the primary stylus member, both during retraction of the primary stylus and during its extension, the restriction being intermediate the ink passage means through the body and the nib portion of the primary stylus member.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial, longitudinal sectional view of the lower portion of a fountain pen incorporating the stylus structure of this invention, with the primary stylus member being shown in fully extended position in solid outline and shown in the retracted position in phantom line.

FIG. 2 is a partial, central longitudinal sectional view of the lower end portion of the stylus-holding structure of FIG. 1, taken in an axial plane at ninety degrees to the plane of the view of FIG. 1.

FIG. 3 is a transverse sectional view taken on the line 3-3 of FIG. 1.

FIG. 4 is a transverse sectional view of the line 4-4 of FIG. 1, on an enlarged scale.

FIG. 5 is a sectional view, on an enlarged scale, taken on the line 5-5 of FIG. 2, illustrating the cross-sectional configuration of the opposed nibs of the primary stylus member.

FIG. 6 is a partial perspective view, with portions thereof cut away in order to show internal features of construction of an alternative embodiment of the stylus mounting structure.

FIG. 7 is a transverse sectional view taken on the lines 77 of FIG. 6, on an enlarged scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there is shown a portion of a barrel 10 of a fountain pen which may be of any type adapted to serve as a reservoir for a supply of ink 11 or to contain auxiliary means, such as flexible sacs or cartridges, or any of the well-known means for holding a desired quantity of ink. In the present case, for simplicity of illustration, the barrel pen is, per se, the reservoir for the supply of ink 11. Accordingly, the barrel 10, at its lower end, is interiorly formed with a tapped portion 12 to receive external threads formed on a plug-like body 13, the threaded engagement being such as to provide a substantially fluid-tight seal. If desired, the lower end face of the plug-like body 13 may be formed with a plurality of spanner wrench holes 14 in order to tighten the threaded engagement between the plug-like body 13 and the threaded portion of the pen barrel 10.

The plug-like body 13 is preferably formed of a synthetic plastic material which while essentially rigid is, at the same time, somewhat or slightly malleable so as to be capable of cold flow. The material of the pluglike body also has a very low coefficient of friction in order to inhibit clogging of the ink and to facilitate extension and retraction of the primary stylus member therethrough. The tetrafluorethylene polymer available commercially under the trademark Teflon is suitable for this purpose.

The upper end of the body 13 is integrally formed with, an elongate cylindrical spring pocket portion 16 that is closed at its upper end, preferably by a blind wall 17. Alternatively, a pin hole or holes may be provided through the end of side walls of the pocket 16 but, if employed, they should be relatively restricted orifices as compared to the ink supply passages for conducting ink from the supply 1 1 to the primary stylus 19. A helical compression spring 18 is disposed within the pocket 16 to normally bias an elongate primary stylus member 19 downwardly through an axial blind bore formed through the plug-like body portion 13. At its lower end, the primary stylus member 19 terminates in a nib portion 20 that is coaxially retractible and extendable into and out of a secondary stylus 21.

The secondary stylus 21 comprises a reduced diameter cylindrical portion of a cup-shaped shell 22 that matingly coaxially receives a cylindrical boss 23 integrally formed on the lower end of the plug-like body 13. The shell portion 22 may be press-fitted, crimped or otherwise tightly secured to the boss 23 to be held against angular displacement relative to the body 13 and barrel 10. In order to limit extension of the nib portion 20 of the primary stylus member 19 outwardly of the secondary stylus 21, the stem portion of the primary stylus member at its lower end defines a shoulder 25 with respect to the nib portion 20, adapted to abut an internal shoulder 26 of the shell 22. It will be observed that the nib portion 20 acts somewhat like a needle valve with respect to the secondary stylus 21.

An ink duct means is provided through the full length of the stem of the primary stylus member 19. Preferably, this takes the form of a pair of longitudinally extending grooves 28 disposed along diametrically opposite longitudinal traces of the stem portion of the primary stylus member 19. With this arrangement, fluid communication is provided between the spring pocket 18 at the upper end of the primary stylus member 19 and an annular chamber 30 defined between the inner surface of the shell 22 and the primary stylus member 19 downwardly adjacent to the lower end face of the boss 23. One or more air vent holes 29 are provided through the cylindrical wall portion of the shell 22, in communication with the chamber 30.

Ink is fed to the primary stylus member 19 by means of a plurality of passages 31 formed through the pluglike body 13. As shown in FIG. 1, the passages 31 are angularly oriented with respect to the longitudinal axis of the primary stylus member 19 such that radially inner ends of the passages open into fluid communication with the bore 15 while radially outer ends of the passages open into communication with an annulus 33 defined between the inner surface of the pen barrel l0 and the outside of the spring pocket 16.

As is best shown in FIG. 2, the nib portion 20 of the primary stylus member 19 is divided into an opposed pair of nibs 35 and 36 that are divided by a slit 37 that extends from the writing end of the nibs to their roots at the shoulder 25 of the primary stylus member. At their roots, the nibs 35 and 36 open into a diametral bore 38 through the stem of the primary stylus member 19, the bore 38 being disposed in a plane including the pair of ink duct grooves 28 so that opposite ends of the bore are in fluid communication with the floors of the grooves 28.

The writing tips of the nibs 35 and 36 may be configured in any desired manner, for example in any of the variety of shapes illustrated in my prior US. Pat. No. 3,247,828. Similarly, the secondary stylus 21 may have its lower end, i.e., the writing end, arranged in a circular, elliptical or other irregular form, for example, any of the forms shown in my prior patent. In any event, it is desired to hold the primary stylus member 19 in a predetermined angular relationship relative to the secondary stylus 21 and the barrel 10, while at the same time maintaining the ink duct grooves 28 of the primary stylus member in registration with the ink passages 31 through the body portion 13.

To this end, a pair of blind bores 40 are drilled into the lower end face of the boss 23, parallelling the axis of the bore 15. As shown in FIG. 4, the pair of blind bores 40 are arranged on diametrically opposite sides of the bore 15 and each receives an oversize pin. As the boss 23 is contained against expansion by the hoop strength of the shell 22, insertion of the oversized pins 41 causes cold flow of the material of the boss 23 to form a pair of ridges 42 which protrude into the pair of duct grooves 28. With this arrangement, the primary stylus member 19 is not only held in the desired angular orientation relative to the secondary stylus 21, but the ridges 42 effect restrictions to the flow of ink through the duct grooves 28, downstream of the passages 31.

An alternative means of keying the parts together and accomplishing the fluid flow restriction is illustrated at F IGS. 6 and 7. In this case, the arrangement of under-sized blind bores 40 and oversize pins 41 is eliminated. Instead, the boss 23 is initially formed, as by molding or machining, with an integrally formed pair of ridges 42a adapted for keying engagement with the duct grooves 28. However, with either arrangement care should be taken in mounting the shell 22 onto the boss 23 to properly angularly orient the writing end of the secondary stylus 21 with respect to the plane of the slit 37 of the nib portion 20 of the primary stylus member. -A convenient means for accomplishing the desired indexing is provided by the air vent 29 which, in the given example, is oriented in substantially the same plane as the plane of the slit 37 of the pair of nibs or of the nib portion 20.

The pen may be employed to draw lines of four different uniform widths. Thus, with reference to FIG. 1 and assuming that a hairline is to be drawn normal to the plane of the drawing, the pen is first tilted left or right in the plane of the figure so that one end only of the slit 37 is in contact with the writing surface. If the pen then is moved normal to the plane of the figure, a hairline will result. If a broader but still thin line is desired to be drawn and with reference to FIG. 1, assuming the pen to be there positioned substantially perpendicularly with respect to a writing surface, if the pen is now drawn horizontally within the plane of the figure, the nib portion 20 will deposit a line having substantially the width of the slit 37 dividing the pair of nibs 35 and 36. If a still broader line is to be drawn, if

the pen as viewed in FIG. 1 is assumed to be moved normally to the plane of the drawing while held substantially perpendicularly with respect to a writing surface, the nib portion will deposit a line having a width at least equal to the width of the lower ends of the nibs 35 and 36, as viewed in FIG. 1.

In order to make dots of large area or the broadest line, sufficient pressure is applied to the pen barrel to depress the primary stylus member 19 into the completely retracted position within the secondary stylus 21, as illustrated in phantom outline in FIG. 1. As will be apparent, if a dot only is desired to be made the desired result is to deliver to the lower end of the secondary stylus 21 only sufficient ink such that when the pressure is released on the pen barrel, the desired dot area will be covered. On the other hand, if it is desired to draw a line having the width of the secondary stylus 21, the desired effect is to deliver through the lower end of the secondary stylus ink at a flow rate only sufficient to fill in the width of the line. In the event of making either a dot or a broad line with the secondary stylus 21, the desired effect is to accomplish re-extension of the primary stylus member 19 at the conclusion of the operation without leaving an excess of ink.

The pen of this invention is adapted to deliver optimum rates of flow of ink for the various widths of line, or a metered increment of ink for dots. The problem is particularly critical in the phases of retraction and extension of the primary stylus member in avoiding surges of ink resulting from the piston action of the primary stylus member. In this connection, the arrangement of the passages 31 by-passing the spring pocket 16 and the location of the restricting ridges 42 intermediate the passages 31 and the nib portion 20 appear to minimize surges of ink flow in extension and retraction of the primary stylus.

While preferred embodiments of this invention have been disclosed, it is to be understood that they are illus trative and not restrictive of the invention.

What is claimed is:

1. In a dual tip fountain pen, the combination comprising:

a pen barrel;

a plug-like body mounted within an end of said barrel, said body being formed with a longitudinally extending bore that is blind at an inner end of said body and that is open at the opposite forward end of said body;

an elongate primary stylus member having a stem portion and a nib portion, said stern portion being shorter than said bore and being matingly telescopically slidably mounted within said bore of said body, the inner end of said stem portion and said blind end of said bore defining a spring pocket whose volume varies with axial displacement of said stem portion in said bore, said nib portion comprising an opposed pair of nibs;

a tubular secondary stylus member, mounted on an outer end of said body, having a shell portion to define an annular chamber around said primary stylus member, said secondary stylus member hav' ing a tubular secondary stylus through which said nib portion of the primary stylus member is extendable and retractable; means to limit extension of said nib portion outwardly of said se con stylus; spring means within sai spring pocket to normally bias said primary stylus member outwardly to an extended position of said nib portion;

ink duct means formed in said stem portion of said primary stylus member comprising an external groove extending longitudinally of said stem portion and communicating said spring pocket at said blind end of said bore with said annular chamber of said secondary stylus member and with the space between said opposed pair of nibs, said groove defining, with the wall of said bore, an ink duct of predetermined cross-sectional area for the flow of ink;

an ink passage means formed in said body to conduct ink from within said barrel to said ink duct means of said primary stylus member, said ink passage means being at least as great in cross-sectional area as the cross-sectional area of said ink duct means of said primary stylus member and having fluid communication with said ink duct means through an opening in the wall of said bore at a position intermediate the ends of said stem portion when said primary stylus member is in said extended position to bypass said spring pocket of said body;

and means defining a restriction in said ink duct means intermediate said opening of said ink passage means in the wall of said bore and said nib portion of said primary stylus member.

2. A fountain pen as in claim 1 in which said ink duct means comprises a plurality of external grooves in said stem portion of said primary stylus member arranged in registration with a like plurality of said ink passage means, said body and said stem portion having cooperating means to maintain a predetermined angular relationship therebetween whereby said primary stylus member and said ink passage means remain in fluid communication during axial telescopic movement of said primary stylus member, said cooperating means also constituting said means defining a restriction for each of said ink duct means.

3. A fountain pen as in claim 2 in which said cooperating means comprises portions of the wall of said bore of said body that project into said grooves of said stem portion of said primary stylus member.

4. A fountain pen as in claim 1 in which body is made of a deformable material and said portions of the wall of said bore comprise deformed portions of the material of said body comprising said means defining a restriction.

5. A fountain pen as in claim 4 in which said body is formed with a plurality of undersized bores mounting a like plurality of oversized pins to define said deformed portions.

6. A fountain pen as in claim 1 in which said spring pocket of said plug-like body includes at least one orifice of lesser cross-sectional area than the cross-sectional area of said ink passage means. 

1. In a dual tip fountain pen, the combination comprising: a pen barrel; a plug-like body mounted within an end of said barrel, said body being formed with a longitudinally extending bore that is blind at an inner end of said body and that is open at the opposite forward end of said body; an elongate primary stylus member having a stem portion and a nib portion, said stem portion being shorter than said bore and being matingly telescopically slidably mounted within said bore of said body, the inner end of said stem portion and said blind end of said bore defining a spring pocket whose volume varies with axial displacement of said stem portion in said bore, said nib portion comprising an opposed pair of nibs; a tubular secondary stylus member, mounted on an outer end of said body, having a shell portion to define an annular chamber around said primary stylus member, said secondary stylus member having a tubular secondary stylus through which said nib portion of the primary stylus member is extendable and retractable; means to limit extension of said nib portion outwardly of said secondary stylus; spring means within said spring pocket to normally bias said primary stylus member outwardly to an extended position of said nib portion; ink duct means formed in said stem portion of said primary stylus member comprising an external groove extending longitudinally of said stem portion and communicating said spring pocket at said blind end of said bore with said annular chamber of said secondary stylus member and with the space between said opposed pair of nibs, said groove defining, with the wall of said bore, an ink duct of predetermined crosssectional area for the flow of ink; an ink passage means formed in said body to conduct ink from within said barrel to said ink duct means of said primary stylus member, said ink passage means being at least as great in cross-sectional area as the cross-sectional area of said ink duct means of said primary stylus member and having fluid communication with said ink duct means through an opening in the wall of said bore at a position intermediate the ends of said stem portion when said primary stylus member is in said extended position to bypass said spring pocket of said body; and means defining a restriction in said ink duct means intermediate said opening of said ink passage means in the wall of said bore and said nib portion of said primary stylus member.
 2. A fountain pen as in claim 1 in which said ink duct means comprises a plurality of external grooves in said stem portion of said primary stylus member arranged in registration with a like plurality of said ink passage means, said body and said stem portion having cooperating means to maintain a predetermined angular relationship therebetween whereby said primary stylus member and said ink passage means remain in fluid communication during axial telescopic movement of said primary stylus member, said cooperating means also constitutinG said means defining a restriction for each of said ink duct means.
 3. A fountain pen as in claim 2 in which said cooperating means comprises portions of the wall of said bore of said body that project into said grooves of said stem portion of said primary stylus member.
 4. A fountain pen as in claim 1 in which body is made of a deformable material and said portions of the wall of said bore comprise deformed portions of the material of said body comprising said means defining a restriction.
 5. A fountain pen as in claim 4 in which said body is formed with a plurality of undersized bores mounting a like plurality of oversized pins to define said deformed portions.
 6. A fountain pen as in claim 1 in which said spring pocket of said plug-like body includes at least one orifice of lesser cross-sectional area than the cross-sectional area of said ink passage means. 